An abutment ( 10,10 A, 10 B, 10 C) for a medical or dental implant has a prosthetic receiving tapered post formed with a locking step ( 10 e) for removably restraining a sleeve member such as an emergence cuff ( 12,12 A). The emergence cuff is receivable on the post of the abutment and has an outer surface configuration which merges confluently with the abutment outer surface. The emergence cuff is formed with a snap on interface ( 12 g) for use with a second sleeve ( 14,14 A) having a complimentary snap on interface ( 14 e). When the second sleeve is open ended, a pin ( 16 ) is shown for closing off the outer end of the second sleeve, if desired.